Q. 255.0( 1 Vote )
Mark the correct alternative in each of the following:
The function f : R → R, f(x) = x2 is
A. injective but not surjective
B. surjective but not injective
C. injective as well as surjective
D. neither injective nor surjective
Given that f : R → R, f(x) = x2
⇒ x2 = y2
⇒ x = ±y
So, it is not one-one.
f(x) = y
⇒ x2 = y
⇒ x = ±√y
But co domain is R.
Hence, f is neither injective nor surjective.
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